Watching the insipid, interminable new “Romeo and Juliet” prompts one to ponder, between regularly checking one’s watch, where it falls on the spectrum of awful Shakespeare. (I’m talking straight Bard, not slangy updates like “10 Things I Hate About You” and “Romeo Must Die.”) Is it worse than Kenneth Branagh’s musical version of “Love’s Labour’s Lost” (2000)? Geoffrey Wright’s Australian-gangster “Macbeth” (2006)? The kitschy, admittedly fun all-star “A Midsummer Night’s Dream” from 1935, or 1936’s “Romeo and Juliet,” with its leads old enough to play their own parents? Yes, yes, yes, and yes. Those were all failures of ambition. Carlos Carlei’s “Romeo and Juliet” is a failure of skill.

It’s a swoony, gauzy, unintentionally comic misfire, apparently aimed at a youth audience weaned on “Gossip Girl” and other CW network staples. (One of the stars of that show, Ed Westwick, appears as a frothingly intense Tybalt.) The young British actor Douglas Booth plays Romeo; he’s introduced with a heaving close-up emphasizing his bare chest and sensitive features. While set in medieval Verona with much attention to the proper pantaloons, this “Romeo and Juliet” feels modernized in the most cynically vapid way. It’s a movie that only a 13-year-old girl with an English paper due could love.

She’d probably get a D, since this production breaks three cardinal rules of “Romeo and Juliet” movies. The first, obviously, is that Romeo should never be prettier than Juliet. Second, and more important, is that a screenwriter can abridge Shakespeare all he wants but he can’t invent new dialogue and alter the language. Julian Fellowes, of “Gosford Park” and “Downton Abbey” fame, seems to think the success of the latter series entitles him to monkey with the Bard at will, so he doesn’t just change lines like Friar Laurence’s “These violent delights have violent ends” to “These violent passions have violent ends.” He strips out whole acres of text and replaces them with passages that clang on the ear, as when Juliet’s nurse (Lesley Manville) gets a gander at Romeo and burbles, “I must say, you have good taste in men!”

The third rule — and, really, it’s just common sense — is that you have to have actors who have some idea of what they’re doing. “Romeo and Juliet” has no good performances, only hapless or overacted ones. The biggest mystery is how Hailee Steinfeld could have navigated the intentionally stilted prose of Mattie Ross so well in the 2010 remake of “True Grit” and come to grief so completely here. She rushes her lines so you can’t understand half of them and seems oblivious to the other half; when she stands on the balcony and asks, “Wherefore art thou Romeo,” she actually seems to be wondering where he is, not why.

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Booth at least enunciates clearly, but he trots through Romeo’s speeches so rhythmically that they turn into iambic mush. All modern audiences have trouble deciphering Shakespeare on the fly, but a gifted cast — like the one in Joss Whedon’s joyful recent adaptation of “Much Ado About Nothing” — can make the sense and import of each line crystal clear. An untutored or misdirected troupe, like the rookies of “Romeo and Juliet,” just drones in Elizabethan.

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There are talents present, some with relevant experience. Damian Lewis may be Brody from “Homeland” to you, but he’s a British-born actor who did time with the Royal Shakespeare Company and played Romeo onstage in 1994. As Lord Capulet, he whips up a righteous snit when his daughter refuses to marry Paris, and his sudden, stuttering fury — “How now, how now, chop-logic!” — gets an unintended laugh from the audience. The same goes for Paul Giamatti as Friar Laurence; a worthy actor stuck in trash, he goes the hambone route early and often, undercutting the drama by overplaying it. Only Natascha McElhone as Lady Capulet and the young Kodi Smit-McPhee as Benvolio evoke a movingly quiet sense of tragedy. Maybe they’re just considering their options.

“Romeo and Juliet” marks the first foray into film production by Swarovski, the Austrian house of jewelry and couture. Accordingly, the costumes are deluxe to the point of occasional silliness and the movie, which was shot on locations in Verona and Mantua, looks good while somehow having the period appropriateness of a high school play. An irritatingly syrupy score by Abel Korzeniowski plays at top volume throughout, and director Carlei proves as inept with the fight scenes as with the drama. His last effort, 1995’s “Fluke,” was about a man who turns into a dog. Hard as it is to believe, he has now done the same to Shakespeare.

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